Electric heater



H. HERRMANN ELECTRIC HEATER Filed June 15. 1924 flBerlin, Germany, have ance wires of the heater.

Patented May 26, 1925.

1 UNIT D" I i HEINRICH HERRMAnN, ban na; GER ANY; assrcr'non To ELECTRTCiTA'IfS-l ensELLsoHAr'r snNIrr-As M. B. it,

BERLIN, GERMANY;

snncrmc HEATER.

Application and June 13, 1924. Serial n6. 719,995.

To all whom it may cmwemr Be it known, that I, Hummer] I'IEIKR- MANN, a citizen of Germany, residing at invented certain new and useful Improvements in Electric Heaters, of which the following is a specitication.

My invention relates to improvements in electric heaters and more particularly in heaters provided with a switch controlling the supply of electric energy to the resist- 1n heaters, such as are now in use, the switch is disposed between the heater and a wall plug or other source of electric energy, and as it is thus attached to thewall plug the leads are frequently torn from the terminals by carelessly handling the heater. The object of the ii'nproveinents is to avoid this drawback. \Vith this and other objectsin view my invention consists in disposing the switch separately from the leads conuecting the heater with the current supply and to an independent cable connected with the heater, the switch being provided at the end of the said cable and having the leads connected to one side only. In this system the cable intermediate the heater and the wall plug is uninterrupted and smooth, so that it can be conveniently handled and rearranged when it is entangled. By thus connecting the switch to the end of a cable it has the character of an ordinary wall switch which can readily be handled by {inexperienced attendants.

For the purpose of explaining the invention an example embodying the same has been shownin the accompanying drawing in which,

Fig. 1, is a plan view associated parts, and I Fig. 2, is a diagrammatical view showing the electric connection.

Inthe example shown in the drawing the a i mratus comprises a heating pad C, and a cable 1% connecting the pad to a suitable source of electric current such as a wall plug A. The heating pad is provided with two resistance wires to and 40 adapted to be connected to the source of electric energy by 103118. of a switch E ,so that either only one of the resistance wires is connected to the plug, or that both are connected in shunt or in series, for producing difl erent of the heater and heating; efiects. The switch E is. connect-p ed to the end" of a cable D attached to the pad at the side opposite to the cable B, and comprising four leads permitting the afore said connections of the resistance wires 10 and Q02, while the cable B consists of two leads. As shown in Fig. 1 the switch comprise two coaxial cylindrical members 6 and.

e rotatable relatively to each other and one provided with terminals connected with the leads of. the cable D, and the other enclosing the bridging members, as is known in the art.

In Fig. 2 I have shown the inner or operative parts of the switch in a diagrammatlcal way. At the side adpicent to the member 6 the member 0 carries eight concentric terminals f, g, h, i, .k, Z, 422, and 91-, and the terminals k and l are connected with the terminal 71., the terminal a is connected by a leads with one of the pins a of the plug A, and the terminals 7' and g7 are connected with each other and the second pin s of the plug A by wires t t and t. The terminal a is connected by a lead 7) with the resistance 102 of the heating pad C, the terminal a is connected by a lead .9 with the resistance w, and the terminal m is connected by a lead 0 with the other ends of the resistance 10 and Q0 T he rotary switch member 6 is provided with bridges qq and r'-r adapted to connect pairs of the terminals of the member 6 according to the position of the member 6 either for switching in one of the resistances or connecting both in shunt or in series. for producing different heating effects. The wires 8 and t are combined into the cable B and the wires 8, t, 0 and p into the cable D. p

I wish it to be understood that I do not limit myself to the type of the switch shown switch, the wires of the cables being connected with the contacts of the switch and in part with the resistances in the pad in such a manner that in the different positions of the switch one resistance only may be circuited or both resistances may be circuited in parallel or in series, or both rcsistances may be cut out.

2. An electric heater comprising aheating pad including two resistances, a duplex cable issuing from said pad and ending in a contact plug, a multiplex cable issuing from another point of said pad and end ing in a manifold switch, the wires of the cables being connected with the contacts of 15 the switch and in part with the resistances in the pad in such a manner that in the different positions of the switch one resistance only may be circuited or both resistances may be circuited in parallel or in series, 20 

